The 11,000 members of the Eau Claire Energy Co-Op are getting the chance to buy into solar electricity at an unusually low price, thanks to a large-scale project just coming online.

The co-op is in the process of installing 2,816 photovoltaic (PV) panels, each rated at 310 watts, in a field outside town. That will create the largest utility-owned solar system in the state with a total rated capacity of 875 kilowatts, according to an article posted at Greentech Media.

Co-op members who take part in the MemberSolar program buy in for $650 per panel, which works out to $2.10 per watt. That’s well below the residential average of $3.48 per watt at the end of 2014, and slightly below the average $2.25/watt for medium-scale commercial projects, as calculated in the U.S. Solar Market Insight report published in March.

The one-time $650 payment members make for a single “subscription unit,” the output from a single panel, goes toward construction and maintenance. Members get a credit on their electric bills for a pro-rated share of the energy produced by the solar farm for the next 20 years.

Lynn Thompson, the co-op’s CEO, says the levelized cost of solar electricity works out to be 8.1 cents per kilowatt hour, compared with the co-op’s standard summer rate of 12.5 cents per kWh and 10.8 cents per kWh during the winter.

MemberSolar estimates each panel will produce an average of 400 kWh or electricity per year, about half of it in June, July and August.

Other projects also underway in Wisconsin

Four other rural electric co-ops already have built solar systems, Greentech Media said, and others are being planned. Because of their smaller size, however, the power is more expensive.

For example, the Clark Electric Cooperative has a 53 kW system with a subscription price of $940 for one 360-watt panel. The Taylor Electric Cooperative launched its 100 kW Bright Horizons solar program in August, putting 274 units up for sale at $945 each. Taylor offers no-interest payment plans through Dec. 31.

The Vernon Electric Cooperative in Westby, Wisconsin, was able to get its per-watt costs below $2 for members when its 305 kW, 1,001-panel facility went into service in May 2014. It was built by Colorado-based Clean Energy Collective.

Dave Maxwell, the co-op’s director of marketing and communication, told GBA that the subscription price was $600 per panel, bringing the cost of electricity to $1.99 per watt. The co-op retained 79 panels for its own use, leaving 113 co-op members to snap up the rest. As with similar community facilities, solar customers are credited on their bills for the power produced by the panels they’ve bought. In September, members were being credited $3.55 per panel.

Maxwell said that the co-op used some of its energy efficiency funds to subsidize the cost of the panels, lowering CED’s original price of $679 to an even $600.

Greentech Media said the size and cost of the programs in Taylor and Clark helped convince the Eau Claire board to invest in a larger system and take advantage of the economies of scale.

“We get calls every day,” Thompson said. “It just takes a lot of time to market. Enthusiasm doesn’t always translate into writing checks.” Ninety customers had purchased a total of 650 panels at last count, leaving some 400 customers needed to fully subscribe the system at that rate.

As many as eight additional community solar projects are on the drawing board elsewhere around the state, including a 500 kW project that would be owned by Madison Gas & Electric. MG&E estimates the cost of the system will be $1.89 per watt.